Is Osama bin Laden willing to listen to constructive criticism from an old friend? If so, a former al-Qaida comrade-in-arms has some advice for him to mark the anniversary of the 9/11 attacks, coinciding this year with the row over Qur'an-burning by an obscure American church that could, some fear, give the organisation a new lease of life.

Noman Benotman is a Libyan ex-jihadi who now devotes himself to combating the message of jihadi extremism. He fought with the mujahideen against the Red Army in Afghanistan but broke with Bin Laden in 2000, after urging him to stop his campaign against the United States because, he argued, it was sabotaging the prospects for change in the Arab world.

Chances are that Benotman's latest appeal calling for a unilateral six-month ceasefire will fall on deaf ears in Waziristan, or wherever Bin Laden is hiding these days. Cynics may dismiss it as a propaganda exercise. But it is worth listening to as an eloquent challenge to al-Qaida from one who once embraced its noxious world view:

"What has September 11 brought to the world except mass killings, occupations, destruction, hatred of Muslims, humiliation of Islam, and a tighter grip on the lives of ordinary Muslims by the authoritarian regimes that control Arab and Muslim states?" Benotman asks.

"Muslims across the world have rejected your calls for wrongful jihad and the establishment of your so-called 'Islamic state' when they witnessed the form this has taken in Iraq. Even the Palestinians consider your 'help' to have had negative repercussions on their cause. Indeed, Israel's control over Gaza has never been stronger and yet some of your supporters have even declared Hamas to be an apostate organisation!

"Most Muslim communities wish to embrace and engage in democracy; they seek justice, peace, freedom, human rights and peaceful co-existence with the rest of the world. Instead, where there was harmony, you brought discord. In New York, your un-Islamic actions have caused hurt, loss, pain and anguish to thousands of innocent people and their families. One consequence is that those Muslims seeking to build a House of God in New York are today being compared to Nazis. And now we hear that on the anniversary of your attack, an American preacher is even planning to burn the Qu'ran in revenge! Indeed, Muslims living in democratic and free societies around the world are now experiencing the consequences of your irresponsible acts."

Benotman speaks with the zeal of the convert, like those former communists who came to excoriate the god that had failed them. He is in demand by academics, the media and governments as an expert on al-Qaida who has near-unique personal experience. He recently joined the Quilliam Foundation, which describes itself as "the world's first counter-extremism thinktank". It is criticised by the left and Islamists for enjoying public funding, paying insufficient attention to western foreign policy and equating all forms of political Islam with extremism and terrorism.

Benotman played a key role in persuading imprisoned members of his old outfit, the Libyan Islamic Fighting Group, to draw up theological "revisions" to the jihadi world view, which directly challenged al-Qaida. He worked closely on this with Saif al-Islam al-Gaddafi, the Libyan leader's son, who likes to advertise his modernising agenda.

The largest-scale "re-education" of jihadis has been in Saudi Arabia, where financial inducements and pressure on prisoners' families combined with a religious message that emphasises the Islamic authority and legitimacy of the Saudi state. Like other Arab regimes, the Saudis sent thousands of young men to fight the communists in Afghanistan and later turned a blind eye to jihad against the US in Iraq to until it began to "blow back" home and threaten them.

Egypt has also seen success with the pioneering "revisions" or "recantations" undertaken by Sayyid Imam al-Sharif - aka Dr Fadl - a once-revered al-Qaida ideologue, from inside his prison cell. Furious reactions from Ayman al-Zawahiri, Bin Laden's deputy, suggested that al-Qaida central took these challenges very seriously.

Conventional wisdom among governments, intelligence services and pundits in the west and the Arab world is that nine years after 9/11, al-Qaida is on the back foot. It is under heavy military pressure in Afghanistan and Pakistan, though still dangerous in Iraq and showing signs of resurgence in Yemen and Somalia. High-profile public criticism from a former jihadi is part of the ideological and propaganda war against it.

It is not enough, of course, to look critically at only one side: Benotman has referred to the problem of the west "talking idealistically and acting brutally" in the Middle East. But that is another story.